Mouthpiece for speaking-tubes or telephones.



PATENTED FEB. 28. 1905.

W. R. KIMBALL.

MOUTHPIEUE FOR SPEAKING TUBES OR TELEPHONES.

APPLICATION FILED 00'I.17,1903.

mm *W woe/whoa M Patented February 28, 1905.

'UNIT ED STATES PATENT OFFICE.

\VILBUR R. KIMBALL, OF NEW YORK, N. Y., ASSIGNOR TO CHRISTOPHER WV. YOUNGMAN, OF NElV YORK, N. Y.

MOUTHPIE CE FOR SPEAKING-TUBES OR TELEPHONES.

SPECIFICATION forming part of Letters Patent No. 783,440, dated February 28, 1905.

Application filed October 17, 1903. Serial No. 177,438.

To (all whom it may concern;

Be it known that I, l/VILBUR R. KIMBALL, a citizen of the United States, and a resident of the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Mouthpieces for Speaking-Tubes or Telephones, of which the following is a specification accompanied by drawings.

This invention relates to mouthpieces for speaking-tubes and telephones; and its objects are to prevent the sound of the voice from be ing heard by those near the speaker and confine the voice so that secrecy may be obtained in the transmission of messages.

Another object of the invention is to improve upon the construction and efiiciency of mouthpieces for carrying out these objects and at the same time increase the volume of sound and distinctness conveyed through the mouthpiece.

Further objects of the invention will hereinafter appear; and to these ends the invention consists of a device for carrying out the above objects embodying the features of construction, combinations of elements, and arrangement of parts having the general mode of operation substantially as hereinafter fully described and claimed in this specification and shown in the accompanying drawings, in which- I Figure 1 is a longitudinal sectional side view of a mouthpiece embodying the invention, and Fig. 2 is a sectional view of the same on the line a: of Fig. 1. Fig. 3 is an end view of the detachable mouthpiece.

Referring to the drawings, A represents a casing of any suitable rigid material, which may be metal, hard rubber, or any other desired material. The outer casing A, of any suitable shape, as shown, is further reinforced by an interior lining of sound-deadening material B, which may be rubber, fibrous material, or any material which is a poor cond uctor of sound. The lining B, as shown, is extendedaround a portion of the end O of the casing A, as shown at D, up to the central tube E, of any suitable shape, which may be of any suitable material-as, for instance, paper, lightness and strength being desired.

Outside of the central tube E are arranged the tubes F, of suitable light material, such as used for tubes and which are preferably open at both ends. 1 have shown the tubes F separated from each other and assembled in the space around the central tube E by way of illustration only,for it is obvious that different constructions may be usedas, for instance, the tubes may be of different cross-sections, either square or round, or of other form and size, and they may be formed in one or more blocks of material, it being only essential that a nest of tubes surround the central tube E.

The object of the tubesFis to break up soundwaves which otherwise interfere by reflection against the sides of a closed chamber, and thereby prevent reverberations and to a large extent eliminate the resonance of the chamber. By this construction elearness and distinctness are obtained.

It is not necessary that the tube E extend for the entire length of the tubes F. I have shown it so extending in this instance by way of illustration only. As shown, the tube E extends beyond the end of the casing A, as at F, and is provided with a nipple G at one side, communicating with the interior of the tube. In this instance a rubber tube H is secured to the nipple, the object being to provide a tube of any suitable character or material communicating with the interior of the tube E, in contradistinction to a mere aperture in the side of a tube, and 1 am not to be understood as limiting myself to the exact construction shown and described, because other constructions will be found equally efiieient. The apparatus so far described is adapted to be attached to the mouthpiece of an ordinary telephone, and, as shown, 1 represents the usual mouthpiece, and upon the casing A are arranged the spring-clips J, adapted to spring over the mouthpiece 1 and maintain the device in position, although other forms of fasteners or screw connection will be found equally efficient. ,lreferably within the clips J is a flexible bulb K, forming a pneumatic seal around the end of the tube E, which is rality of additional tubular passages within tightly pressed against the mouthpiece I when the device is clamped in position.

The object of the tube H communicating with the tube E is primarily to lead off the compressed air and surplus air-currents without interfering with the transmission of the soundwaves, and it has been found that by providing a tube H of appreciable length, as described, the escaping sound-waves are attenuated to such an extent that they become practically inaudible at a few inches distance. It will also be seen that according to this construction the air impulses are led off in a direction transverse to the direction of travel of the sound-vibrations, and this without interference with said souml-vibrations, which are transmitted more clearly and distinctly to the diaphragm than heretofore.

At the transmitting end of the device a suitable flexible, elastic, or pliable mouthpiece 0 may be provided, which, as shown, lits about or within the end of the casing A and is preferably provided with a grating of porous material P to prevent interference with the tubes inside of the casing.

if desired, a pneumatic edge may be provided for the mouthpiece in any suitable manner as, for instance, by suitably securing a flexible pneumatic tube 0 upon the edge of the mouthpiece. By this means the elastic pressure of the pneumatic edge against the face of the speaker prevents the escape of sound-waves.

Obviously some features of this invention may be used without others, and the invention may be embodied in widely-varying forms.

Therefore without limiting the invention to the apparatus shown and described nor enumerating equivalents, 1 claim, and desire to obtain by Letters Patent, the following:

1. A mouthpiece for speaking-tubes and telephones, comprising a casing forming a substantially closed chamber when in use, and. a plurality of tubular passages within the easing for breaking up the sound-waves, thereby reducing the resonance of the chamber, for substantially the purposes set forth.

2. A mouthpiece for speaking-tubes and telephones, comprising a casing forming a chamber adapted to be arranged in substantial axial alinement with the mouthpiece of the telephone and close or fill the opening thereof, and a tube or passage-way arranged transversely to the axis of the chamber and communicating with the chamber at the forward end nearest the telephone, for conducting ex- ,cess'of air-pressure from the chamber andat the same time rendering the sound-waves leaving said tube or passage-way substantially inaudible, for substantially the purposes set forth.

3. A mouthpiece for speaking-tubes and tclephones, comprising a casing forming a chamber having a passage-way therethrough, a pluthe casing for breaking up the sound waves thereby reducing the resonance of the chamher, and means for separating the air-currents from the sound-waves, for substantially the purposes set forth.

4. Amouthpiece for speaking-tubes and telephones, comprising a casing, a plurality of passages within the casing for reducing the resonance'thcreof, and means for separating the air-currents from the sound-waves, for substantially the purposes set forth.

5. A mouthpiece for a telephone or speaking-tube and for analogous uses, having a main body portion composed of stifl material having a suitable elastic, plastic, flexible or pliable lining with a pneumatic edge connected to said lining, thereby enabling the inner surfaces of the mouthpiece to follow and conform to the facial movements while speaking, thus preventing the escape of sound-waves, for substantially the purposes set forth.

6. A mouthpiece forspeaking-tubes and telephones, designed to muffle the voice of the speaker, said device consisting of a still casing having an interior lining of sound-dezulening material, and provision for venting the mouthpiece to atmospheric air, whereby the air-currents are separated from the sound-waves, and the voice muiiled, for substantially the purposes set forth.

7. A mouthpiece for speaking-tubes and telephones, comprising a casing having a lining of sound-deadening material, and a tube or passage-way communicating with the interior of said casing and extendingtherefrom beyond the exterior of the casing, for separating the air-currents from the sound-waves, for substantially the purposes set forth.

8. A mouthpiece forspeaking-tu bes and telephones, comprising a casing forminga chamber adapted to be arranged in substantial axial alinement with the mouthpiece of the speaking-tube or telephone, and cover or fill the opening thereof, and a tube or passage-way communicating with the interior of said chamber at the forward end of the chamber nearest the telephone, and extending therefrom beyond the exterior of the casing, for conducting the excess of air-pressure from the chamber and at the same time render the soundwaves leaving said tube or passage-way substantially inaudible, forsubstantially the purposes set forth.

9. A mouth piece for speaking-tubes and telephones, comprising a casing open at both ends and adapted to be arranged in front of the speaking-tube or telephone in axial alinement therewith, with one end covering or closing said speaking-tube or telephone, and a tube or passage-way communicating with the interior of said casing at the forward end of the casing nearest the telephone and extending therefrom beyond the exterlorof the easing, for conducting the excess of alr-pressure pheric air, whereby the air-currents are separated from the sound-Waves and the voice mufiled, for substantially the purposes set 5 forth.

In testimony whereof I have signed this specification in the presence of two subscribing Witnesses.

WILBUR R. KIMBALL.

WVitnesses:

A. L. OBRIEN, E. VAN ZANDT. 

